Abstract:

A package substrate, a manufacturing method thereof, a base package
module, and a multi-layered package module having package substrates
laminated on upper and lower portions of a base package module are
provided. The base package module includes a base metal substrate, a
first metal oxide layer that is formed on the base metal substrate to
have a cavity therein, a device that is mounted in the cavity on the base
metal substrate and insulated by the first metal oxide layer formed on a
sidewall in the cavity, and a conductor that is connected to the device
and a wiring pad formed on the first metal oxide layer on the base metal
substrate. The package substrate includes a wiring pad, a conductor line,
a second metal oxide layer having an opening that exposes a device, and a
via that is connected to the wiring pad through a connection pad in the
second metal oxide layer.

Claims:

1. A package substrate, comprising:a plate-shaped metal oxide layer; andat
least one metal via that is formed to penetrate at least one portion of
the metal oxide layer and to have a thickness equal to that of the metal
oxide layer, wherein the metal oxide layer is formed by performing
oxidation on the entire surface of a metal substrate without a mask, and
the metal via corresponds to a portion that is not oxidized during the
oxidation of the metal substrate for forming the metal oxide layer.

2. The package substrate of claim 1, wherein the metal is aluminum, and
the metal oxide layer is alumina.

3. The package substrate of claim 1, further comprising a metal plate that
is disposed in the metal oxide layer.

4. The package substrate of claim 1, further comprising one or more
through-holes that penetrate predetermined portions of the metal oxide
layer.

5. The package substrate of claim 4, further comprising vias that are
formed along inner walls of the through-holes to extend on a portion of
the metal oxide layer.

6. The package substrate of claim 1, further comprising a device mounting
portion that is constructed by forming a metal layer on a lower surface
of the metal oxide layer and forming a cavity on an upper surface of the
metal layer.

7. The package substrate of claim 6, wherein a device mounted on the
device mounting portion and the package substrate are connected to each
other through a conductor line.

8. A multi-layered package module having layered package substrates,
wherein the package substrates are laminated by contacting connection
pads that are disposed on upper and lower portions of vias.

9. A base package module, comprising:a base metal substrate;a first metal
oxide layer that is formed on the base metal substrate to have a cavity
therein;a device that is mounted in the cavity on the base metal
substrate and insulated by the first metal oxide layer formed on a
sidewall in the cavity; anda conductor that is connected to the device
and a wiring pad formed on the first metal oxide layer on the base metal
substrate.

10. The base package module of claim 9, further comprising a via that
connects upper and lower portions.

11. A multi-layered package module having a base package module and
package substrates laminated on upper and lower portions of the base
package module, wherein each of the package substrates comprises:a wiring
pad;a conductor line;a second metal oxide layer having an opening that
exposes a device; anda via that is connected to the wiring pad through a
connection pad in the second metal oxide layer.

12. The multi-layered package module of claim 11, wherein upper portions
of the wiring pad, the conductor line, and the device in the opening of
the package substrate are filled with an insulating layer.

13. The base package module of claim 9, wherein the first metal oxide
layer is formed on a bottom portion of the cavity where the device is
mounted.

14. The base package module of claim 13, wherein an electrode is formed on
the bottom portion of the cavity on the first metal oxide layer.

15. The multi-layered package module of claim 8, wherein the base package
module and the package substrates are adhered to each other with an
adhesive layer.

16. The multi-layered package module of claim 8, wherein a penetrating
through-hole or a non-penetrating hole is formed.

17. The multi-layered package module of claim 8, wherein a passive device
is formed on the metal oxide layer of the package substrate.

18. The multi-layered package module of claim 8, wherein surface mounting
type of parts are mounted on the metal oxide layer of the uppermost
package substrate or base package module.

19. The multi-layered package module of claim 8, wherein an active device
or a passive device is disposed in an inner portion of the package
substrate.

20. A method of manufacturing a multi-layered package module, wherein the
forming of the cavity and the metal oxide layer comprises:forming the
metal oxide layer by performing selective anodic oxidation on the base
metal substrate; andforming the cavity by selectively etching the metal
oxide layer to expose the base metal substrate.

21. The method of claim 20, wherein, in the selectively etching of the
metal oxide layer, a portion of the metal oxide layer is left on the base
metal substrate.

22. A method of manufacturing a package substrate, comprising:forming
recesses by removing predetermined portions of upper and lower surfaces
of a metal substrate;leaving a predetermined thickness of a metal
constituting the metal substrate in portions where the recesses are not
formed by oxidizing the entire surface of the metal substrate without a
mask until portions of the metal substrate corresponding to the recesses
are completely oxidized; andforming vias by polishing both surfaces of
the resulting product until metal surfaces left in the portions where the
recesses are not formed are exposed.

23. The method of claim 22, wherein the recesses are formed by etching and
removing the predetermined portions.

24. The method of claim 22, wherein the recesses are formed by pressing
with a pressing apparatus.

25. The method of claim 22, wherein the forming of the recesses
comprises:forming recesses having non-uniform depths on the upper surface
of the metal substrate; andforming recesses having non-uniform depths on
the lower surface of the metal substrate.

26. The method of claim 25, further comprising:forming the recesses of the
metal substrate in an asymmetrical structure;remaining a predetermined
thickness of a metal constituting the metal substrate in portions where
the recesses are not formed by oxidizing the metal substrate to form the
metal oxide layer; andforming a device mounting portion having a metal
layer on a lower surface thereof by polishing a lower surface of the
resulting product until metal surfaces left in the portions where the
recesses are not formed are exposed and by etching an upper surface of
the metal oxide layer.

Description:

TECHNICAL FIELD

[0001]The present invention relates to a multi-layered package module and
a manufacturing method thereof and, more particularly, to a multi-layered
package module using a metal substrate and a manufacturing method
thereof.

BACKGROUND ART

[0002]As the degree of integration of semiconductor devices is increased
and various functions are provided to the semiconductor devices, the
packaging process tends to be changed from a process suitable for a small
number of pins of a package to a process suitable for a large number of
pins of the package. In addition, a conventional structure for mounting
the package on a printed circuit board (PCB) has been replaced with a
surface mounting structure. Many types of packages with the surface
mounting structure have been proposed, for example a small outline
package (SOP), a plastic leaded chip carrier (PLCC), a quad flat package
(QFP), a ball grid array (BGA), and a chip scale package (CSP).

[0003]A printed circuit board (PCB) or a low temperature co-fired ceramic
(LTCC) board associated with the semiconductor device needs to have
thermal, electrical, and mechanical stability. Conventionally, the PCB
has been manufactured by using expensive ceramic substrates or resin
substrates made of a polyimide-based resin, a fluoride-based resin, or a
silicon-based resin. The LTCC board has been manufactured by using a
ceramic substrate. Since the ceramic substrate or the resin substrate
used for the LTCC board or the PCB is an insulator, an insulating
material does not need to be applied after a through-hole process.

[0004]However, since the resin substrate has poor water-resistance and
heat-resistance, the resin substrate has a problem in that the resin
substrate is not usable for a chip-carrier substrate. Although the
ceramic substrate has better heat resistance than that of the resin
substrate, the ceramic substrate has problems in that the ceramic
substrate is also expensive and hard to process, and has a high
production cost.

[0005]On the other hand, recently, as products tend to be manufactured in
a small-sized thin type, a board having a thin thickness and a flat
surface has been demanded. As an approach for implementing such a thin
and flat product, cavities are formed on pre-determined portions of the
substrate, and the chips or parts are mounted in the cavities.

DISCLOSURE OF INVENTION

Technical Problem

[0006]In a conventional method of forming the cavities, the cavities have
been formed by drilling a resin substrate. When using the method, cavity
processing time and cost are increased. In addition, since a deviation of
the cavities is large, parts mounted therein may be easily slanted, so
that it is difficult to maintain a predetermine flatness of the
substrate. Moreover, since the resin used for the substrate has poor
thermal and mechanical characteristics, if the parts are mounted in the
cavities formed in the resin substrate, serious stress and deformation
may occur in the resin substrate.

[0007]The above information disclosed in this Background section is only
for enhancement of understanding of the background of the invention and
therefore it may contain information that does not form the prior art
that is already known in this country to a person of ordinary skill in
the art.

[0008]The present invention has been made in an effort to provide a
package substrate and a multi-layered package module using the package
substrate having advantages of overcoming problems of a printed circuit
board (PCB) constructed with a ceramic substrate or a resin substrate.
The present invention has also been made in an effort to provide a method
of manufacturing the package substrate and a method of manufacturing the
multi-layered package module.

Technical Solution

[0009]An exemplary embodiment of the present invention provides package
substrate including a plate-shaped metal oxide layer, and at least one
metal via that is formed to penetrate at least one portion of the metal
oxide layer and to have a thickness equal to that of the metal oxide
layer, wherein the metal oxide layer is formed by oxidizing the entire
surface of a metal substrate without a mask, and the metal via
corresponds to a portion that is not oxidized during the oxidation of the
metal substrate for forming the metal oxide layer.

[0010]In the above embodiment, the metal may be aluminum and the metal
oxide layer may be alumina.

[0011]The package substrate may further include a metal plate that is
disposed in the metal oxide layer.

[0012]The package substrate may further include one or more through-holes
that penetrate predetermined portions of the metal oxide layer. In
addition, the package substrate may further include vias that are formed
along inner walls of the through-holes to extend onto a portion of the
metal oxide layer.

[0013]The package substrate may further include a device mounting portion
that is constructed by forming a metal layer on a lower surface of the
metal oxide layer and forming a cavity on an upper surface of the metal
layer. In addition, a device mounted on the device mounting portion and
the package substrate may be connected to each other through a conductor
line.

[0014]Another embodiment of the present invention provides a multi-layered
package module having layered package substrates, wherein the package
substrates are laminated by contacting connection pads that are disposed
on upper and lower portions of vias.

[0015]Yet another embodiment of the present invention provides a
multi-layered package module having a base package module and package
substrates laminated on upper and lower portions of the base package
module, wherein each of the package substrate includes a wiring pad, a
conductor line, a second metal oxide layer having an opening that exposes
a device, and a via that is connected to the wiring pad through a
connection pad in the second metal oxide layer.

[0016]In the above embodiment, upper portions of the wiring pad, the
conductor line, and the device in the opening of the package substrate
may be filled with an insulating layer.

[0017]Still another embodiment of the present invention provides a base
package module, including a base metal substrate, a first metal oxide
layer that is formed on the base metal substrate to have a cavity
therein, a device that is mounted in the cavity on the base metal
substrate and insulated by the first metal oxide layer formed on a
sidewall in the cavity, and a conductor that is connected to the device
and a wiring pad formed on the first metal oxide layer on the base metal
substrate.

[0018]In the above embodiment, the base package module may further include
a via that connects upper and lower portions.

[0019]The first metal oxide layer may be formed on a bottom portion of the
cavity where the device is mounted. In addition, an electrode may be
formed on the bottom portion of the cavity on the first metal oxide
layer.

[0020]The base package module and the package substrates may be adhered to
each other with an adhesive layer.

[0021]A penetrating through-hole or a non-penetrating hole may be formed.

[0022]A passive device may be formed on the metal oxide layer of the
package substrate.

[0023]Surface mounting types of parts may be mounted on the metal oxide
layer of the uppermost package substrate or base package module.

[0024]An active device or a passive device may be disposed in an inner
portion of the package substrate

[0025]Further still another embodiment of the present invention provides a
method of manufacturing a multi-layered package module, wherein the
forming of the cavity and the metal oxide layer includes forming the
metal oxide layer by performing selective anodic oxidation on the base
metal substrate, and forming the cavity by selectively etching the metal
oxide layer to expose the base metal substrate.

[0026]In the above embodiment, in the selectively etching of the metal
oxide layer, a portion of the metal oxide layer may be left on the base
metal substrate.

[0027]Further still another embodiment of the present invention provides a
method of manufacturing a package substrate, including forming recesses
by removing predetermined portions of upper and lower surfaces of a metal
substrate, leaving a predetermined thickness of a metal constituting the
metal substrate in portions where the recesses are not formed by
oxidizing the entire surface of the metal substrate without a mask until
portions of the metal substrate corresponding to the recesses are
completely oxidized, and forming vias by polishing both surfaces of the
resulting product until metal surfaces remaining in the portions where
the recesses are not formed are exposed.

[0028]In the above embodiment, the recesses may be formed by etching and
removing the predetermined portions.

[0029]The recesses may be formed by pressing with a pressing apparatus.

[0030]The forming of the recess may include forming the recesses having
non-uniform depths on the upper surface of the metal substrate, and
forming the recesses having non-uniform depths on the lower surface of
the metal substrate.

[0031]The method may further include forming the recesses of the metal
substrate in an asymmetrical structure, leaving a predetermined thickness
of a metal constituting the metal substrate in portions where the
recesses are not formed by oxidizing the metal substrate to form the
metal oxide layer, and forming a device mounting portion having a metal
layer on a lower surface thereof by polishing a lower surface of the
resulting product until metal surfaces remaining in the portions where
the recesses are not formed are exposed and by etching an upper surface
of the metal oxide layer.

Advantageous Effects

[0032]According to the present invention, the multi-layered package module
is constructed and manufactured by using a metal substrate. Therefore,
since the substrate used for the multi-layered package module according
to the present invention is inexpensive and easy to process in comparison
to the PCB and the LTCC board, it is possible to manufacture the
multi-layered package module at a low cost.

[0033]According to the present invention, since the multi-layered package
module is constructed by using a metal substrate, it is possible to
obtain the multi-layered package module having good thermal reliability
and good heat releasing efficiency in comparison to the PBB and the LTCC
board.

[0034]In addition, in the multi-layered package module according to the
present invention, the cavity is formed by etching the metal oxide layer
formed by using the metal substrate, the cavity can be easily processed,
and a deviation of the cavity can be reduced.

[0035]In addition, according to the present invention, since the
multi-layered package module is formed by using the metal substrate, it
is possible to obtain good thermal and mechanical characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS

[0036]FIG. 1 is a cross-sectional view illustrating a multi-layered
package module according to an embodiment of the present invention.

[0037]FIGS. 2 to 6 are cross-sectional views for explaining a structure of
a package substrate and a manufacturing method thereof according to an
embodiment of the present invention.

[0038]FIGS. 7 to 9 are cross-sectional views for explaining a structure of
a package substrate and a manufacturing method thereof according to
another embodiment of the present invention.

[0039]FIGS. 10 to 12 are cross-sectional views for explaining a structure
of a package substrate and a manufacturing method thereof according to
still another embodiment of the present invention.

[0040]FIGS. 13 and 14 are cross-sectional views for explaining a structure
of a package substrate and a manufacturing method thereof according to
further still another embodiment of the present invention.

[0041]FIGS. 15 to 21 are cross-sectional views for explaining a structure
of a package substrate and a manufacturing method thereof according to
further still another embodiment of the present invention.

[0042]FIGS. 22 to 28 are cross-sectional views for explaining a structure
of a package substrate and a manufacturing method thereof according to
further still another embodiment of the present invention.

[0043]FIGS. 29 to 33 are cross-sectional views for explaining a base
package module and a manufacturing method thereof according to an
embodiment of the present invention.

[0044]FIGS. 34 to 39 are cross-sectional views for explaining a base
package module and a manufacturing method thereof according to another
embodiment of the present invention.

[0045]FIGS. 40 to 42 are cross-sectional views for explaining a connection
pad structure of a package substrate and a formation method thereof
according to an embodiment of the present invention.

[0046]FIGS. 43 and 44 are cross-sectional views for explaining a
connection pad structure of a package substrate and a formation method
thereof according to another embodiment of the present invention.

[0047]FIGS. 45 to 47 are cross-sectional views for explaining a
multi-layer laminating method for package substrates and a multi-layer
lamination structure according to an embodiment of the present invention.

[0048]FIGS. 48 and 49 are cross-sectional views for explaining a
multi-layer laminating method for package substrates and a multi-layer
lamination structure according to another embodiment of the present
invention.

[0049]FIG. 50 is a cross-sectional view for explaining a multi-layer
laminating method for package substrates and a multi-layer lamination
structure according to still another embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0050]Hereinafter, exemplary embodiments of the present invention are
described in detail with reference to the accompanying drawings.

[0051]A multi-layered package module according to the present invention is
manufactured by using a metal substrate in order to overcome drawbacks of
a printed circuit board (PCB) or a low temperature co-fired ceramic
(LTCC) board manufactured by using a resin substrate or a ceramic
substrate. Therefore, since the metal substrate used for the
multi-layered package module according to the present invent is
inexpensive and easy to process in comparison to the PCB and the LTCC
board, it is possible to manufacture the multi-layered package module at
a low cost.

[0052]Since the metal substrate used to manufacture the multi-layered
package module according to the present invention has excellent heat
releasing efficiency in comparison to the PCB and the LTCC board, circuit
devices that are vulnerable to heat can be mounted thereon. In addition,
since the LTCC board thermally contracts during a sintering process, a
variation in size of a pattern thereon is increased. However, in the case
of using the metal substrate according to the present invention, the
multi-layered package module is manufactured at a low temperature, so
that thermal contraction thereof does not occur.

[0054]FIG. 1 is a cross-sectional view illustrating a multi-layered
package module according to an embodiment of the present invention.

[0055]Referring to FIG. 1, the multi-layered package module includes a
base package module 200 and a plurality of package substrates 100a, 100b,
and 100c that are sequentially laminated on the base package module 200.
In the base package module 200, a metal oxide layer 44 is formed in a
base metal substrate 40, and a cavity 47 is formed at a predetermined
portion of the metal oxide layer 44, so that metal oxide layer 44 can be
disposed on a side surface of the cavity 47. A device (chip) 48, for
example an active device or a passive device, is attached (mounted) on
the base metal substrate 40 in the cavity 47 and insulated by the metal
oxide layer 44. The base metal substrate 40 may be constructed with an
aluminum substrate, and the metal oxide layer 44 may be constructed with
an aluminum oxide (alumina) layer. Wiring pads 61 are disposed at both
sides of the device 48, and electrodes 48a of the device 48 are connected
to the wiring pads 61 through wire lines 50. Another metal oxide layer 44
may be formed under the wiring pads 61. Particularly, in the case of
connecting the base metal substrate to ground, the metal oxide layer 44
may not be formed.

[0056]The first package substrate 100a is laminated on the base package
module 200. The first package substrate 100a includes a second metal
oxide layer 18 having an opening to expose the wiring pads 61, the wire
lines 50, and the device 48, and a via 20 that is connected to a
predetermined portion of the metal oxide layer 18 through the wiring pad
61 to a connection pad 62. The upper portion of the wiring pads 61, the
wire lines 50, and the device 48 in the through-hole 22 is filled with an
insulating layer 60, for example, a polyimide layer. The insulating layer
60 may not be formed if it is not needed. The base package module 200 and
the first package substrate 100a are adhered to each other by using an
adhesive layer 66. The first package substrate 100a functions as a
connecting member for connecting to the to-be-laminated second package
substrate 100b. In addition, passive devices (not shown) may be formed on
the first package substrate 100a.

[0057]The second package substrate 100b is laminated on the first package
substrate 100a and the through-hole 22. The second package substrate 100b
includes a metal oxide layer 18 and a via 20 that is connected to the
connection pads 62 formed on the upper and lower surfaces of the metal
oxide layer 18. A passive device 64 is mounted on the central portion of
the second package substrate 100b. The first package substrate 100a and
the second package substrate 100b are adhered to each other by using an
adhesive layer 66.

[0058]Similar to the second package substrate 100b, the third package
substrate 100c is laminated on the second package substrate 100b. The
third package substrate 100c includes a via 20 that is connected to the
connection pad 62. A passive device 64 is mounted on the central portion
of the third package substrate 100c. Surface mounting parts may be
mounted on the third package substrate 100c. The second package substrate
100b and the third package substrate 100c are adhered to each other by
using an adhesive layer 66.

[0059]In the embodiment shown in FIG. 1, although the three package
substrates 100a, 100b, and 100c are laminated, only two package
substrates or a larger number of the package substrate may be laminated,
as needed. Hereinafter, all the package substrates are collectively
denoted by reference numeral 100. In addition, on the lower surface of
the base package module 200, another base package module or another
package substrate may be laminated, or a via 20a may be formed to be
connected to an external connecting land or the like. Hereinafter,
various types of the package substrates 100, various types of the base
package modules 200, and various types of the manufacturing methods are
described, and they are implemented based on the construction shown in
FIG. 1. In addition, a laminating structure of the package substrates 100
and a laminating method thereof are described in detail.

[0060]A package substrate and manufacturing method thereof will be
described.

[0061]FIGS. 2 to 6 are cross-sectional views for explaining a structure of
a package substrate and a manufacturing method thereof according to an
embodiment of the present invention.

[0062]Referring to FIGS. 2 to 6, a metal substrate 12, for example an
aluminum substrate, is prepared. Mask layers 14 are formed on the upper
and lower surfaces of the metal substrate 12. Some portions of the metal
substrate 12 are selectively etched by using the mask layers 14 to form
recesses 16.

[0063]Referring to FIG. 4, the mask layers 14 are removed. Referring to
FIG. 5, the entire upper and lower surfaces of the metal substrate 12 are
subjected to anodic oxidation to form a metal oxide layer 18 and a metal
layer 12a that is disposed at an inner portion of the metal oxide layer
18. In a case where the metal substrate 12 is constructed with an
aluminum substrate, the metal oxide layer 18 is constructed with an
aluminum oxide layer.

[0064]Referring to FIG. 6, the metal oxide layers 18 formed on the upper
and lower surfaces of the metal layer 12a are subjected to lapping or
polishing to be planarized, so that the vias 20 of which upper and lower
portions are exposed are formed in the metal layer 12a. As a result, a
package substrate 100 where the vias 20 are formed at predetermined
portions, for example at both side portions of the metal oxide layer 18,
is obtained.

[0065]FIGS. 7 to 9 are cross-sectional views for explaining a structure of
a package substrate and a manufacturing method thereof according to
another embodiment of the present invention.

[0066]Referring to FIG. 7, a metal substrate 12, for example an aluminum
substrate, is prepared. A through-hole 22 is formed to penetrate the
metal substrate 12. According to a desired design, a plurality of the
through-holes 22 may be formed in various sizes. In FIG. 7, a
through-hole 22 having a wide area is formed at the central portion of
the metal substrate, and through-holes 22 having a narrow area are formed
at both side portions thereof.

[0067]Referring to FIG. 8, the entire surfaces of the metal substrate 12
in which the through-hole 22 is formed are subjected to anodic oxidation
to form a metal oxide layer 18. As a result, in the metal substrate 12, a
metal layer 12a is formed at an inner portion of the metal oxide layer
18. In a case where the metal substrate 12 is constructed with an
aluminum substrate, the metal oxide layer 18 is constructed with an
aluminum oxide layer.

[0068]Referring to FIG. 9, the metal oxide layers 18 formed on the upper
and lower surfaces of the metal layer 12a are subjected to lapping or
polishing to be planarized, so that the vias 20 of which upper and lower
portions are exposed are formed in the metal layer 12a. As a result, a
package substrate 100 where the vias 20 are formed at both side portions
of the metal oxide layer 18 in which the through-hole 22 is formed is
obtained.

[0069]FIGS. 10 to 12 are cross-sectional views for explaining a structure
of a package substrate and a manufacturing method thereof according to
still another embodiment of the present invention.

[0070]Referring to FIG. 10, the package substrate 100 manufactured in FIG.
9 is prepared. Namely, the package substrate 100 where the vias 20 are
formed at both side portions of the metal oxide layer 18 in which the
through-hole 22 is formed is obtained.

[0071]Referring to FIGS. 11 and 12, a second via 20a and a third via 20b
are formed in the through-hole 22 formed in the metal oxide layer 18. The
second via 20a is formed so as to fill the through-hole 22 by using a
plating process, a silk screen process, or the like. The third via 20b is
formed so as to not fill the through-hole 22 completely by forming the
metal layer along the surface thereof. As a result, a package substrate
100 where the vias 20, 20a, and 20b in various shapes are formed in the
metal oxide layer 18 is obtained. In the specification, the vias are
collectively denoted by reference numeral 20.

[0072]FIGS. 13 and 14 are cross-sectional views for explaining a structure
of a package substrate and a manufacturing method thereof according to
further still another embodiment of the present invention.

[0073]More specifically, as shown in FIG. 13, a metal substrate 12, for
example an aluminum substrate, is prepared. Molds 304 having grooves 302
are disposed on the upper and lower surfaces of the metal substrate 12.
As shown in FIG. 14, the metal substrate 12 is pressed by using the molds
304 to form the metal substrate 12 having recesses 16. Since aluminum
used for metal substrate 12 is soft and easy to process, mass production
of the metal substrates 12 having the recesses 16 can be easily
implemented by performing the pressing with the molds.

[0074]Subsequently, processes that are the same as those of FIGS. 5 and 6
are performed. Namely, the entire surfaces of the metal substrate 12
having the recesses 16 are subjected to anodic oxidation and the two-side
polishing process, so that a package substrate 100 where the vias 20 are
formed on both side portions of the metal oxide layer 18 is obtained.

[0075]FIGS. 15 to 21 are cross-sectional views for explaining a structure
of a package substrate and a manufacturing method thereof according to
further still another embodiment of the present invention.

[0076]Referring to FIGS. 15 and 16, a metal substrate 12, for example an
aluminum substrate, is prepared. First mask layers 14a are formed on the
upper and lower surfaces of the metal substrate 12. Some portions of the
metal substrate 12 are selectively etched by using the first mask layers
14a to form first recesses 16a.

[0077]Referring to FIGS. 17 and 18, the first mask layers 14a are removed.
Subsequently, second mask layers 14b are formed on the upper and lower
surfaces of the metal substrate 12 in which the first recesses 16a are
formed. Some portions of the metal substrate 12 are selectively etched by
using the second mask layers 14b to form second recesses 16b. The
recesses 16 may be formed by performing the pressing process using the
molds similarly to the aforementioned embodiment.

[0078]Referring to FIGS. 19 and 20, the second mask layers 14b are
removed. The entire surfaces of the metal substrate 12 are subjected to
the anodic oxidation to form a metal oxide layer 18. As a result, a metal
layer 12a is formed at the inner portion of the metal oxide layer 18. In
a case where the metal substrate 12 is constructed with an aluminum
substrate, the metal oxide layer 18 is constructed with an aluminum oxide
layer.

[0079]Referring to FIG. 21, the metal oxide layers 18 formed on the upper
and lower surfaces of the metal layer 12a are subjected to lapping or
polishing to be planarized, so that the vias 20 of which upper and lower
portions are exposed are formed in some portions of the metal layer 12a
and a metal plate 21 is formed in the inner portion thereof. As a result,
a package substrate 100 where the vias 20 are formed on both side
portions of the metal oxide layer 18 and the metal plate 21 is formed in
the inner portion thereof is obtained.

[0080]In this manner, according to the embodiment, by sequentially
adjusting the thickness of the metal substrate, after the anodic
oxidation, it is possible to form the metal plate at the inner portion of
the metal substrate as well as to form the vias. Accordingly, the metal
plate functions as wiring and as a ground plate and a power plate.

[0081]FIGS. 22 to 28 are cross-sectional views for explaining a structure
of a package substrate and a manufacturing method thereof according to
further still another embodiment of the present invention. In FIGS. 22 to
28, a package substrate 100 where a device mounting portion constructed
with a metal layer is disposed in the metal oxide layer and the vias 20
are formed in the metal oxide layer is obtained.

[0082]Referring to FIG. 22, a base metal substrate 40, for example an
aluminum substrate, is prepared. Mask layers 42 are formed on the upper
and lower surfaces of the metal substrate 40. The first mask layer 42
formed on the upper surface of the base metal substrate 40 exposes a wide
area of the upper surface of the base metal substrate 40, and the first
mask layer 42 formed on the lower surface of the base metal substrate 40
exposes a narrow area of the lower surface thereof.

[0083]Referring to FIG. 23, some portions of the base metal substrate 40
are selectively etched by using the mask layers 42 to form recesses 52 in
the upper and lower surfaces of the base metal substrate 40. The recesses
formed on the upper surface of the base metal substrate 40 have a wide
width, and the recesses 52 formed on the lower surface of the base metal
substrate 40 have a narrow width.

[0084]Referring to FIGS. 24 and 25, the mask layers 42 are removed. The
entire surfaces of the base metal substrate 40 are subjected to the
anodic oxidation to form a metal oxide layer 54. As a result, metal
layers 40a are formed on the center portion and both side portions of the
metal oxide layer 54. In a case where the base metal substrate 40 is
constructed with an aluminum substrate, the metal oxide layer 54 is
constructed with an aluminum oxide layer.

[0085]Referring to FIG. 26, the metal oxide layer 54 formed on the upper
and lower surfaces of the metal layer 40a is subjected to lapping or
polishing to be planarized. As a result, the metal layer 40a formed on
the central portion of the metal oxide layer 54 is exposed at the lower
surface to form the device mounting portion 56, and the metal layers 40a
formed on both side portions thereof forms the vias 20 of which upper and
lower portions are exposed.

[0086]Referring to FIGS. 27 and 28, the metal oxide layer 54 on the device
mounting portion 56 is selectively etched to form a cavity 47 in which a
device, for example an active device, is to be mounted. Subsequently,
passive devices 58 and wiring pads 61 are formed on the metal oxide layer
54 at both sides of the device mounting portion 56. The passive devices
58 may be mounted on a wiring layer (not shown) of the metal oxide layer
54 in a surface mounting manner. Alternatively, the passive devices may
be formed by using semiconductor processes.

[0087]A base package module and a manufacturing method thereof will now be
described.

[0088]In the aforementioned schematic view of FIG. 1, one device 48 is
mounted on the base metal substrate 40. However, as described below, a
plurality of the devices 48 may be mounted on the base metal substrate
40, as needed.

[0089]FIGS. 29 to 33 are cross-sectional views for explaining a base
package module and a manufacturing method thereof according to an
embodiment of the present invention.

[0090]Referring to FIG. 29, a base metal substrate 40, for example an
aluminum substrate, is prepared. First mask layers 42 are formed on the
upper and lower surfaces of the metal substrate 40. The first mask layer
42 formed on the upper surface of the base metal substrate 40 partially
exposes the upper surface of the base metal substrate 40, and the first
mask layer 42 formed on the lower surface of the base metal substrate 40
is formed on the entire lower surface thereof.

[0091]Referring to FIGS. 30 and 31, some portions of the base metal
substrate 40 are subjected to selective anodic oxidation by using the
first mask layers 42 to form a metal oxide layer 44. Namely, the metal
oxide layer 44 is formed on a portion of the base metal substrate 40.
Subsequently, the first mask layers 42 are removed.

[0092]Referring to FIG. 32, second mask layers 46 that cover some portions
of the metal oxide layer 44 and the entire lower surface of the base
metal substrate 40 are formed on the base metal substrate 40.
Subsequently, the metal oxide layer 44 is etched by using the second mask
layer 46 as an etch mask to form a cavity in which the device is to be
mounted. According to the present invention, since the cavity 47 is
formed by using the etching process, the cavity 47 can be easily
processed, and a deviation in size of the cavity can be reduced.

[0093]Referring to FIG. 33, the second mask layers 46 are removed.
Subsequently, the device 48 is adhered and secured in the cavity 47 by
using an adhesive (not shown) such as epoxy. According to the present
invention, since the device 48 is mounted in the cavity of the base metal
substrate 40, excellent thermal and mechanical characteristics can be
obtained in comparison to a convention PCB or LTCC board, so that it is
possible to prevent deformation caused from stress. The device 48 is
insulated by the metal oxide layer 44 disposed on the side portions in
the cavity 47.

[0094]Next, by forming wiring pads 61 on the metal oxide layer 44 of the
base metal substrate 40 and connecting the electrodes of the device 48 to
the wring pads 61, a base package module 200 is obtained.

[0095]FIGS. 34 to 39 are cross-sectional views for explaining a base
package module and a manufacturing method thereof according to another
embodiment of the present invention.

[0096]Referring to FIG. 34, a portion of a surface of the base metal
substrate 40, for example an aluminum substrate, is subjected to
selective anodic oxidation by using a mask process to form a metal oxide
layer 44. Namely, the metal oxide layer 44 is formed on some regions of
the base metal substrate 40.

[0097]Referring to FIGS. 35 to 37, a mask layer 46 is formed on the base
metal substrate 40 to cover a portion of the metal oxide layer 44 and the
entire lower surface of the base metal substrate 40. Subsequently, the
metal oxide layer 44 is etched by using the mask layer 46 as an etch mask
to form a cavity 47 where a device is to be mounted. Next, the mask layer
46 is removed.

[0098]Referring to FIGS. 38 to 39, the device 48 is adhered and secured in
the cavity 47 by using an adhesive material (not shown) such as epoxy.
Consequently, the device 48 is insulated by the metal oxide layer that is
formed on a side surface of the cavity 47. Next, the electrode 48a of the
device 48 and the wiring pad 61 formed on the metal oxide layer 44 may be
connected to each other by using the wire line 50.

[0099]Particularly, in FIG. 39, a separate lower electrode 51 is formed on
a bottom surface of the cavity, and an upper electrode 48a of the device
48 is connected to the wiring pad 61 by using the wire line 50. As a
result, the device 48 having electrodes on the upper and lower portions
thereof can be mounted, and the lower electrode 51 can be connected to
different signal lines other than the base metal substrate 40.

[0100]A connection pad of the package substrate and a forming method
thereof will now be described.

[0101]FIGS. 40 to 42 are cross-sectional views for explaining a connection
pad structure of a package substrate and a formation method thereof
according to an embodiment of the present invention.

[0102]Referring to FIG. 40, various package substrates 100 are prepared,
similar to the aforementioned embodiments. In FIG. 40, for the
convenience of description, the package substrate 100 shown in FIG. 6 is
exemplified. Namely, in FIG. 40, the package substrate 100 where the vias
20 are formed on both side portions of the metal oxide layer 18 is
prepared.

[0103]Referring to FIG. 41, metal layers 62a are formed on the upper and
lower surfaces of the package substrate including the metal oxide layer
18 and the vias 20. The metal layers 62a may be used to form connection
pads, passive devices, and metal wiring layers. The metal layers 62a are
formed by attaching metal sheets on the upper and lower surfaces of the
package substrate or by using a plating process.

[0104]Referring to FIG. 42, the metal layers 62a are wet-etched or
dry-etched by using a masking process and an etching process to form
connection pads 62, metal wiring, or passive devices. The connection pads
62 are formed on the surface of the metal oxide layer 18 or the surface
of the via 20. The connection pads 62 may be used to connect a plurality
of the package substrates 100. Alternatively, the connection pads 62, the
metal wiring, or the passive devices may be formed by using a silk screen
process or the like.

[0105]FIGS. 43 and 44 are cross-sectional views for explaining a
connection pad structure of a package substrate and a formation method
thereof according to another embodiment of the present invention.

[0106]Referring to FIG. 43, various package substrates 100 are prepared,
similar to the aforementioned embodiments. FIG. 43, for the convenience
of description, the package substrate 100 shown in FIG. 6 is exemplified.
Namely, in FIG. 43, the package substrate 100 where the vias 20 are
formed on both side portions of the metal oxide layer 18 is prepared.

[0107]Referring to FIG. 44, the connection pads 62, the metal wiring, or
the passive devices are directly formed on the upper and lower surfaces
of the package substrate 100 including the metal oxide layer 18 and the
vias 20. The connection pads 62, the metal wiring, or the passive devices
are formed by using a silk screen process, a semi-conductor process, or
the like. The connection pads 62 are formed on the surface of the metal
oxide layer 18 or the surface of the via 20. The connection pads 62 may
be used to connect a plurality of the package substrates 100.

[0108]A multi-layered laminating method for the package substrate
including the connection pad and a structure thereof will now be
described.

[0109]Hereinafter, a multi-layer laminating method for a package substrate
provided with connection pads is described. The same multi-layer
laminating method may be used to laminate a base package module. A
multi-layer laminating method using a package substrate will be
described.

[0110]FIGS. 45 to 47 are cross-sectional views for explaining a
multi-layer laminating method for package substrates and a multi-layer
lamination structure according to an embodiment of the present invention.

[0111]More specifically, a plurality of the aforementioned package
substrates 100 where the connection pads 62 are formed are prepared. In
each of the package substrates 100, the vias 20 are formed in the metal
oxide layer 18, and the connection pads 62 are formed on the upper and
lower portions of the vias 20. According to a desired design of each of
the package substrates 100, the connection pads 62 or the vias 20 may be
formed in different shapes.

[0112]The package substrates 100 where the connection pads 62 are formed
are laminated by using adhesive layers 66. Therefore, the adhesive layers
66 are disposed between the package substrates 100. During the lamination
of the package substrates 100, the package substrates 100 are connected
to each other through the connection pads 62.

[0113]In FIGS. 45 to 47, the same elements as those of the aforementioned
embodiments are denoted by the same reference numerals.

[0114]FIGS. 48 and 49 are cross-sectional views for explaining a
multi-layer laminating method for package substrates and a multi-layer
lamination structure according to another embodiment of the present
invention.

[0115]Referring to FIG. 48, a plurality of the aforementioned package
substrates 100 where the connection pads 62 are formed are prepared. In
each of the package substrates 100, the vias 20 are formed in the metal
oxide layer 18, and the connection pads 62 are formed on the upper and
lower portions of the vias 20. According to a desired design of each of
the package substrates 100, the connection pads 62 or the vias 20 may be
formed in different shapes. Subsequently, adhesive layers 66 are
selectively formed on the upper and lower surfaces of the package
substrates 100 by using a silk screen process or the like.

[0116]Referring to FIG. 49, the package substrates 100 where the
connection pads 62 are formed are laminated and adhered to each other.
Therefore, the adhesive layers 66 are disposed between the package
substrates 100. During the lamination of the package substrates 100, the
package substrates 100 are connected to each other through the connection
pads 62.

[0117]FIG. 50 is a cross-sectional view for explaining a multi-layer
laminating method for package substrates and a multi-layer lamination
structure according to still another embodiment of the present invention.

[0118]Referring to FIG. 50, multi-layered package substrates 100 are
prepared, similar to the aforementioned embodiment. In addition,
through-holes 70 that penetrate all the multi-layered package substrates
100 or non-penetrating holes 72 that penetrate some of the multi-layered
package substrates 100 are formed. In addition, the through-holes 70 are
filled with a metal material to form vias 76. The non-penetrating holes
72 are also filled with a metal material to form vias 78. In FIG. 50,
reference numeral 74 denotes a contact metal layer. As shown in FIG. 50,
after the package substrates are laminated, the multi-layered package
substrates are processed in various shapes so as to be used as a
multi-layered package module.

[0119]While this invention has been described in connection with what is
presently considered to be practical exemplary embodiments, it is to be
understood that the invention is not limited to the disclosed
embodiments, but, on the contrary, is intended to cover various
modifications and equivalent arrangements included within the spirit and
scope of the appended claims.